This invention relates to methods of biologically degrading pentachlorophenol.
Pentachlorophenol (PCP) is a widely used biocide which has been reported to uncouple oxidative phosphorylation, to complex with respiratory proteins in mitochondria, and to inhibit active transport of ions in bacteria [Edgehill et al., Eur. J. Appl. Microbiol. Biotechol., 16, 179-184 (1982)]. It has been applied to crops as a herbi-cide, and it is also used as an insecticide, fungicide, an algicide and a disinfectant. PCP is particularly widely used as a wood preservative, to inhibit molds and wood boring insects.
Due to its widespread use and its acute toxicity (many species of fish are reportedly killed at PCP concentrations of 0.6 mg/l or less), it is important to prevent build-up as a result of any of the above uses; the soil and water adjacent wood treatment plants or adjacent structures that include treated wood are particularly vulnerable to PCP contamination.
Certain bacteria have been reported to degrade PCP. However, PCP toxicity reportedly is not limited to any particular species, and PCP-degrading bacteria exhibit a limited tolerance for PCP.
Edgehill et al., report isolation of an Arthrobacter which exhibits constant growth in concentrations of PCP between 10-135 mg/l [Edgehill et al., supra; Edgehill et al., Applied and Environmental Microbiol, 45, 1122-1125 (1983)].
Watanabe, Soil Sci. Plant Nutr., 19, 109-116 (1973), reports a bacteria of genus considered to be Pseudomonas or a closely related genus, which degrades PCP, grows optimally at concentrations below 100 ppm, and exhibits no growth at PCP concentrations of 200 ppm.
Suzuki, J. Environ. Sci. Health, B12(2), 113-127 (1977), discloses isolation of a Pseudomonad which degrades PCP at PCP concentrations of 40 mg/l but exhibits a lagged growth period when the PCP concentration exceeds that level.